


Monthly MonStar Cycles

by Zehntacles



Category: Star vs. The Forces Of Evil
Genre: Egg Laying, F/F, MonStar - Freeform, Monster - Freeform, Oviposition, septarian - Freeform
Language: English
Status: Completed
Published: 2019-12-22
Updated: 2019-12-22
Packaged: 2021-02-25 22:42:21
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,847
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21893089
Author URL: https://archiveofourown.org/users/Zehntacles/pseuds/Zehntacles
Summary: Like most girls Star has to endure a monthly biological cycle, but unlike most girls hers involves being a monster princess from another dimension.  Story portrays fan AU character MonStar Butterfly.
Comments: 3
Kudos: 28





	Monthly MonStar Cycles

Being a magical princess from an alien kingdom made Star’s new life on Earth a sometimes confusing and complicated ordeal that she had to navigate. Being a half-mewman half-septarian creature made things even trickier when everyone else around her was a human while her skin was covered in soft grey scales and her hair was a unique light blue. Despite that she often felt welcome among her new friends, and her host family on Earth was very open to caring for her and treating her like she belonged. She very much enjoyed staying on Earth while she learned to use her magic and attending school every day with her best friend Marco was a treat she didn’t get to normally enjoy back home.

Today however was different, Star had stayed home from school while Marco had gone on ahead. Letting him know that she simply wasn’t feeling good and wanted to be left alone in bed. Mr. and Mrs. Diaz had left the house as well to go do their errands and daily routine, leaving Star laying on her bed in her nightgown. Covers kicked off her body while she breathed deeply due to the discomfort she was feeling at the moment. “Stupid body... why do I have to go through this every month?” She complained. “At least I caught it in time instead of having it happen in school...” Today was hard enough without having to also avoid an audience for her issues.

Which was when her door suddenly swung open as an uninvited visitor entered.

“Hey Star.” Janna said, looking down at her phone.

“Waaah!” Star shouted, grabbed her covers and pulling them up over her body as quickly as she could. “Janna!? What are you doing here!? How did you get in!?”

“I heard you skipped school so I came over to hang out.” Janna said, sitting on the side of Star’s bed and finally looking up from her phone. “As for how I got in, tah dah. Marco’s keys. I lifted them off him when we were talking about you.”

“But why, didn’t Marco tell you I was sick?”

“Yeah, but like, it’s gotta be some weird Mewni sickness right? Probably won’t effect me.” Janna said confidently. “So what’s wrong with you?”

“I... it’s private.” Star said, pulling the covers up a little further. Her lizard tail flicking at the end in annoyance at having her privacy invaded.

“C’mon, it can’t be that bad? Like, is it weird thing? Some kind of skin shedding or something?” Janna asked brashly, not taking the hint that Star wanted to be left alone.

“Janna, it’s not... really something I wanted... ugh...” Star said, curling up under the covers.

“Whoa, you look kinda bad. Do you need me to get you some water or something?” Janna asked, standing up and putting her hand on Star’s forehead. “You are really warm right now.”

“Janna... please... I’m... ugh... can’t hold it back...” Star grumbled, pulling the covers off her body and panting harder. When the fabric came off Janna could see clearly under Star’s nightgown there was something different about her friend.

“Whoa. Did you get fat?” Janna asked in disbelief, looking at the bulge in Star’s stomach as she laid her arms and legs out apart.

“Not... fat...” Star moaned out. “Janna please... don’t tell anyone.”

“Yeah okay, I guess so.” Janna said curiously. “What’s going on though.”

“Egg... egg’s coming.” Star said through hot breaths, using her fingers to pull up her nightgown on her body. Janna watched with fascination as Star spread her legs apart further, not wearing panties underneath and exposing her pussy that was currently dripping wet.

“You’re gonna lay an egg!?” Janna said half in shock and half in excitement. “Oh I have to watch this.”

“You’re going... to watch!?” Star asked, the dark red color of the heart marks on her cheeks glowing redder as Janna sat on the end of the bed.

“Of course, how often does someone get to watch a show like this?” Janna said, leaning forward to see as Star moaned deeper and lifted her hips up off the bed. Unable to argue with her anymore as it was coming. “Hey, I think I can see it.”

“Big... it’s a big one...” Star moaned, her pussy lips pushed out as Janna watched the white egg begin to press forward. Hey eyes rolling backwards as she used her muscles to press it further and further up against her vagina and spread it open. Tongue hanging out the side of her mouth as she gasped for air.

“That really does look like a big one.” Jana said, watching Star’s face as she tried to force the egg out of her body. “You’re like soaked down here, does this feel good for you?” Reaching her hand out carefully Janna ran her fingers around Star’s tensed vagina, her finger running up and touching her clit.

“J-J-Janna!” Star moaned but unable to get much more out of her mouth, her clawed fingers digging into her bed as she shivered and felt Janna’s thumb press and rub slowly against her clit. “Pushing! It’s pushing harder!” Letting out a cry Star arched her back, coming against Janna’s thumb and squirting lightly onto the bed.

“Whoa. That... was awesome.” Janna said, smiling to herself while Star continued to moan. “Jeez, after all that you’re like, only half way through. How many of these do you have to push out?”

“One... just one...” Star moaned, her legs shaking after her orgasm and hard push. But the pressure between her legs didn’t let her forget that this task wasn’t over. She felt Janna’s body lift off the bed and continued to lay on her back, staring straight up as she tried to get the strength to keep pushing. Her embarrassment gone compared to her need to finish.

“Okay, turn around onto your stomach.” Janna instructed as she stood over her.

“Why... are you naked?” Star asked, looking her friend over to see she wasn’t completely naked, still in a pair of yellow panties but otherwise her clothes had been tossed aside on the floor.

“Because you squirt like a fountain when you’re excited and this is going to get messy.” Janna said, pulling Star’s nightgown up the rest of the way over her head. “Hey, did these get bigger too? They look different from before.” Her hand reached down and squeezed one of Star’s breasts, making the monster princess shiver.

“They’re swollen... hormones from the egg...” Star grumbled, rolling over slowly as Janna guided her onto all fours. Resting her upper body on her elbows and her head on a pillow, Janna moved behind her again. She could feel her snuggle up against her leg and rest her tail against the crook of Janna’s neck. “You’re really close to me...”

“Well if I’m going to help you I have to be.” Janna said, Star shuddering as she felt her soft fingers press against her pussy lips where her egg was trying to pass. Gently pressing and sliding around it in a circle to try and help guide it out. Star moaned out feeling Janna’s fingers wiggle and press inside of her body as it helped pull the egg along. “How did you ever do something like this by yourself before?”

“Usually... not... this big...” Star said while panting, her light blue hair a pooled mess around her neck as her ass picked up further into the air.

“Maybe we have to lube you up a little bit more?” Janna said and Star moaned as she felt Janna lick along her tail.

“That’s really... sensitive.” Star complained into her pillow but was soon distracted feeling her clit rubbed again by Janna’s fingers. Her muscles working on instinct now as her pussy squeezed and pushed against the egg inside her.

“You’re coming right along.” Janna said confidently, deciding to help out a little more and use both her hands to dig in lightly inside of Star’s pussy and pull at the egg. Her fingers were coated in Star’s juices as she felt the egg come along further and further into her grip from Star’s shivering hips..

Star let out a high pitched squeal, biting into her pillow as the egg finally spilled out of her pussy onto the bed below her. Janna watched as she squirt into the air again, soaking the sheets beneath her and letting her hips finally drop onto the bed as she gasped for air from the orgasm and pressure release. Turning her head to the side Star pulled her hair off of her face, her tail twitching against Janna’s cheek as her muscles adjusted to finishing their task.

“Dang, this is really big!” Janna said in amazement. “It’s even bigger than my hand. You’re still kinda open down here. I wonder if...”

“Hey!” Star shouted, feeling a large object press into her pussy suddenly. Looking behind herself she could see Janna had pressed her hand inside of her. “That’s... too sensitive!”

“Oh, sorry! You just uh... looked like you could take it after all that.” Janna said, slowly pulling her hand out of Star’s pussy as her muscles began to return to normal as she relaxed. As she lay on the bed Janna suddenly laid down next to her, holding her egg against her chest. “So all that trouble for this, huh? Is a little Marco monster going to hatch out of this thing?”

“No, it’s not fertilized.” Star said groggily. “Hey, did you just insinuate I had sex with Marco!?”

“Well, yeah? I mean how else did you lay this thing?”

“I’m on the pill.” Star explained, but the confused expression on Janna’s face told her that wasn’t much of an answer. “My mom got them for me before I left Mewni. It’s so that if I... y’know... if I do have sex I won’t get pregnant with a fertilized egg.”

“Wow, your mom is kind of cool.” Janna said, holding the egg up in her hands to admire it. “Making sure you can have safe sex like that. I don’t think my parents even realize I know what sex is.”

“You have no idea what she puts me through.” Star grumbled.

“Hey can I keep this?” Janna asked.

“You want to keep that?” Star asked. “My egg. The egg that came out of my body.”

“Well you’re not going to use it, right?” Janna asked. “Besides, I helped get it out of you.”

“Fine, but don’t tell anyone about it okay?”

“Sure, as long as I can help you with the next one. This was fun.” Star was reluctant to accept but it was nice to know if she had another problem like this there was help for her. So agreeing to keep Janna in the loop with her monthly womanly issues the two friends spent the rest of the day hanging out together. The Mewni princess enjoying a very pleasurable morning and a fun day after while her Earth friend got to take home a little trophy for a job well done.

**Author's Note:**

> Cover art by Step at https://www.pixiv.net/en/users/52992850


End file.
